The election returns show Labour spent $2.58million on election advertising during the 2017 election campaign while National spent $300,000 less at $2.55million.
National got better bang for its buck.
Once the taxpayer-funded broadcasting allocations for each party were added in, National spent about $3.40 for each vote it secured while Labour spent $3.85.
Overall, it was a dramatic change of fortunes for Labour since 2014, when it was cash-strapped and spent just $1.27million on the campaign led by David Cunliffe - slightly less than the Green Party and less than half National's spending.
Labour general secretary Andrew Kirton said it was satisfying to be able to match National's spending.
A flood of donations after Ms Ardern's move to the leadership had made it possible.
The donations returns are due in April.
Labour's return shows some of the financial cost of the leadership change from Mr Little to Ms Ardern just seven weeks before the election.
It had to scrap $114,000 worth of Little hoardings and replace them with Ardern hoardings, which cost a further $200,000.
Ms Ardern's campaign was focused on youth, and Labour spent more than four times as much on social media advertising than National - from gay dating site Grindr to Facebook and Google.
It spent $475,400 for advertising on Facebook and Google compared with National's $101,255.
The returns also showed Labour spent about $225,000 with Moss Group, an Australian advertising agency, for Mr Little's campaign including the ``fresh approach'' slogan and some design and advertising work much of which had to be scrapped.
There were also $38,500 worth of television ads produced for Mr Little that were of little use once he stepped down.
Ad agency Curative, owned by Ms Ardern's friend Eddy Royal, was also paid $62,000, which Mr Kirton said was for advertising work done in the initial stages of Ms Ardern's leadership before the new agency was selected.
Mr Kirton said New Zealand firm Augusto took over for the television advertisements and online advertising for Ms Ardern, but some of the work done by Moss Group was still used.
Augusto, which specialises in sports advertising such as All Blacks' sponsors AIG and adidas, was paid $202,000 for its work for Labour.
National's return shows it stuck with the same advertising brains as 2014, Peter Moore and Sue Worthington.
Their company was paid $475,400 in fees and production costs.
That included an advertisement featuring runners which were intended to represent National compared to Labour, the Greens and NZ First. National paid $13,800 for the 10 people recruited as those runners.
The returns show that the Green Party spent $818,500 while New Zealand First spent $666,150.
The Opportunities Party spent just over $1million on advertising for its first campaign, much of it funded by founder Gareth Morgan.
The parties also got taxpayer-funded broadcasting allocations to spend on television and radio, as well as online videos.
Although Labour spent more of its own money on election advertising, National had a larger broadcasting allocation because the allocation goes off the party's support in the previous election and polling since.
It was the first election in which the parties could use their broadcasting allocation for online advertising.
Labour's return showed it had used $105,586 of its allocation of about $925,000 on Facebook advertising and $545,000 on TV.
The returns show National dedicated almost all of its allocation to radio and television and paid for its online advertising out of its own funds rather than the allocation.
Party general secretary Greg Hamilton said that was because restrictions on campaign broadcasting meant parties could not use their own money on radio and television advertising time so wanted to maximise that allocation.
Labour spent about $26,000 on robo-calling which was yet to be added to its return while National spent about $29,000.
Robo-calling is automatic calling in which a recorded message from the leader of the party was played to whoever answered the phone.
